PITTSBURGH—A man who said he was a heroin addict was tackled by parishioners after he snatched a 90-year-old woman's purse while she was taking communion during Mass, police and the church's pastor said.

The Rev. John Dinello, pastor of the Most Holy Name of Jesus Parish, said parishioners were told to be alert because of similar thefts in the city's Troy Hill neighborhood.

The priest noticed a man arrive 10 minutes late for the 9 a.m. service Sunday, then move up several pews during the sermon, so the priest motioned for his ushers to be vigilant.

Eric Csurilla moved up again as the elderly woman took communion and he grabbed her change purse, police and the priest said. He put the purse, which contained $2 and a department store credit card, inside a church bulletin and tried to run, they said.

Instead, two ushers—one of them Steve McCauley, the off-duty chief of the Port Authority of Allegheny County police transit police—grabbed Csurilla. Another parishioner, "Big Mike" Chemosky, hurdled two pews and put the suspect in a choke hold.

"He wasn't going anywhere," Chemosky said. "This is my home. This is my church, where I feel safe. When someone steals from your church, you feel violated."

Chemosky said the suspect told him "he has an addiction. He was sorry and he was glad he was getting caught. Hopefully, it was true."

Online court records didn't list an attorney for Csurilla, 31, of Braddock. He remained jailed Monday unable to post bail on a charge of theft.

"It's sad that it had to happen in a church, but we're not going to let it happen here in our community or in our homes," Dinello said.

"If you don't stop it, it just takes over."