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Suspected serial killer Billy Chemirmir has been indicted on two additional counts of capital murder in Dallas County, court documents show.

Prosecutors allege he smothered two 83-year-old women during the summer of 2016 before robbing them.

He allegedly killed Juanita Purdy on July 31 and then killed Leah Corken on Aug. 19, just a few weeks apart, court records show.

Chemirmir, 47, had previously been charged with 12 counts of capital murder in connection with the deaths of elderly women in Dallas and Collin counties.

Civil lawsuits accuse him of killing at least eight others. Chemirmir had already been linked to the deaths of Purdy and Corken in previously filed lawsuits against an upscale senior living center.

One set of lawsuits allege Chemirmir posed as a maintenance worker at The Tradition-Prestonwood, where he killed and robbed eight elderly women and one elderly man.

RELATED: Suspected serial killer linked to more deaths of elderly people, lawsuit alleges

The suits say the senior living center failed to provide adequate security and hid Chemirmir's connection to the string of deaths.

In each death, excluding the death of 89-year-old Solomon Spring, they were found smothered in their homes.

Spring had been found in a pool of blood inside his residence.

Additional lawsuits have been filed against another upscale retirement community, Preston Place, where Chemirmir is alleged to have smothered seven women to death while posing as a maintenance worker as well.

RELATED: New lawsuit in Billy Chemirmir case names additional victims, details on alleged slayings

According to one lawsuit, the alleged killings at Preston Place occurred in less than a five-month period between Oct. 31, 2017, and March 18, 2018.

The lawsuits claim Preston Place failed to protect itself residents and inform them of previous crimes that occurred in the community.

In most of the cases, the deaths were initially deemed natural.

Chemirmir has been indicted in the deaths of:

Phyllis Payne, 91, on May 14, 2016 at Edgemere Senior Living

Phoebe Perry, 94, on June 5, 2016

Juanita Purdy, 83, on July 31, 2016 at The Tradition

Leah Corken, 83, on Aug. 19, 2016 at The Tradition

Norma French, 85, on Oct. 8, 2016 at The Tradition

Doris Gleason, 92, on Oct. 29, 2016 at The Tradition

Minnie Campbell, 83, on Oct. 31, 2017 at Preston Place

Carolyn MacPhee, 81, on Dec. 31, 2017

Rosemary Curtis, 76, on Jan. 17, 2018

Mary Brooks on Jan. 31, 2018

Martha Williams, 80, on March 4, 2018 at Preston Place

Miriam Nelson, 81, on March 9, 2018 at Preston Place

Ann Conklin, 82, on March 18, 2018 at Preston Place

Lu Thi Harris, 81, on March 20, 2018

He is linked through lawsuits to the deaths of:

Joyce Abramowitz, 82, on July 20, 2016 at The Tradition

Margaret White, 87, on Aug. 28, 2016 at The Tradition

Solomon Spring, 89, on Oct. 2, 2016 at The Tradition

Glenna Day, 87, on Oct. 15, 2016 at The Tradition

Diana Delahunty was killed on Dec. 5, 2017 at Preston Place

Mamie Dell Miya, killed on Dec. 8, 2017 at Preston Place

“Jane Doe” was killed on Dec. 10, 2017 at Preston Place

Doris Wasserman, 90, on Dec. 23, 2017

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