A year ago Wednesday, as 17-year-old James Coakley celebrated July 4 at a family barbecue at his grandmother’s house in Roxbury, a car pulled up, and someone pointed a gun and shot Coakley to death. He was one of four people killed in separate shootings that holiday weekend.

This year, with fears of a similar early July eruption and with six nonfatal shootings since Friday, police are planning to be out in force on Wednesday.

“We’ve typically seen ­increased violence during the first week of July,’’ said Boston Police Commissioner Edward F. Davis, who said the department will substantially ­increase patrols through the week, particular in areas known for violence in Roxbury, Dorchester, and Mattapan.

Since Friday, six men, mostly teenagers, were wounded in the latest spate of violence that stretched from Dorchester to Mattapan.

“We’re handling each of those shooting incidents separately and looking to hold people accountable,’’ Davis said in a telephone interview.

A woman who lives on ­Angell Street in Dorchester, where a 19-year-old was shot in the shoulder Friday night at a backyard party, said her street has in recent years been plagued by violence and drug dealing, which she and several other residents attributed to one family that lives nearby.

The woman, who has lived on the street for 20 years, ­declined to give her name for fear of retaliation.

“It’s a shame, but many of the residents who live here ­aren’t going to say anything ­because they’re in fear, and, in the meantime, things continue to get worse,’’ she said. “Come the holiday Wednesday, I think I’ll leave, because I don’t want to be around if anything happens. I’m afraid, and my daughter’s so afraid that she hasn’t been able to sleep since the shooting Friday.”

The Greater Love Tabernacle is located several blocks away from Angell Street, on the opposite side of Blue Hill Avenue. The Rev. William E. ­Dickerson II, pastor, said residents in any of the city’s hotspots have to be diligent in working to stop violence.

“Residents have to work ­together to take back their community; it’s a collaborative effort,’’ Dickerson said in a telephone interview. “The ones who are sick and tired of dealing with violence on the street, have to rally together to bring about peace in the area.”

Davis said Mayor Thomas M. Menino’s Problem Properties Task Force has been a ­major tool in cutting down on the spread of violence, drugs, prostitution or other quality-of-life problems associated with an address.

“That task force has been busy picking residences throughout the city and dealing with them one by one,” he said. “Clearly this residence [on ­Angell Street] is a place where we’ll have to take a look.’’

Davis declined to discuss how many additional police ­officers will be deployed for the holiday. “July Fourth is usually a difficult night for us, and we’re looking closely at our ­intelligence files and at individuals known to engage in this type of behavior.”

He said that with the holiday falling midweek, there may be fewer alcohol-related ­arrests.

No arrests have been made in Coakley’s slaying.

“I’ve cried enough, and I don’t think any parent should have to go through the pain that I’ve had,’’ Dynyella Priest, Coakley’s mother, said in a telephone interview Monday. “The violence has got to stop. . . . If you’re someone out there doing it, stop and make something of your life, because no parent should have to endure what I have.”

Priest turned 39 on Friday, but she said she will start celebrating her birthday on July 4 this year to reclaim the day.

“I will celebrate to the fullest,” she said. “I’m not disregarding his death, but I have to move on with my son’s legacy. That’s all I can do at this point. I just wish all this violence would stop. I don’t care if anybody is held accountable for taking his life, it won’t make me feel any better.”